Influence of dynamic strain aging pre-treatment on creep-fatigue behavior in 316L stainless steel

Stress controlled creep-fatigue tests were carried out for hot rolled and dynamic strain aging pre-treated 316L stainless steel different loading levels at 550 °C. For both pre-treatment state materials, dynamic strain aging was found to manifest itself macroscopically as displacement or mean strain abrupt jumps during cyclic deformation. Comparing with hot rolled material, by DSA pre-treatment, the creep-fatigue cyclic strain amplitude is decreased, the cycle at the 1st abrupt displacement jump is postponed and the material creep-fatigue life is effectively prolonged. Moreover, it is found that, the material creep-fatigue life monotonically increases with pre-deformation strain, no matter the maximum pre-deformation stress is larger than the maximum creep-fatigue applied stress or not.